Quick answer
What Is Toe-Brachial Index (TBI) Test?
The toe-brachial index (TBI) test is a needle-free test that compares the blood pressure in your big toe with the blood pressure in your arm. It is used to assess peripheral artery disease, especially in diabetes, kidney disease, or older age, when stiff ankle arteries make ABI results less reliable.
Sources01 / Understanding the procedure
About Toe-Brachial Index (TBI) Test
What Is a TBI Test
The toe-brachial index test, or TBI, compares the blood pressure in your big toe with the blood pressure in your arm. If the arteries that carry blood to the feet are narrowed, the pressure in the big toe drops compared with the arm. This test is often done together with the ankle-brachial index (ABI) test, which measures the pressure at the ankle.
How It Works in Brief
A small cuff is placed at the base of the big toe, and a light sensor is placed on its tip. The cuff is inflated until blood flow stops, then slowly deflated. The pressure at which blood flow returns is picked up by the sensor, then divided by the higher of the two arm blood pressures.
Why the Big Toe
In diabetes, chronic kidney disease, or older age, the artery walls at the ankle can harden due to calcification. Stiff arteries are hard for the cuff to compress, so the ABI result appears normal or too high even though blood flow is actually reduced. The small arteries in the toes harden much less often, so the TBI gives a more reliable picture.
Reading TBI Results
- Above 0.70: generally considered normal.
- 0.70 or lower: indicates narrowing of the leg arteries.
- Big toe pressure below 30 mmHg: blood flow is very poor, so foot wounds are slow to heal and need prompt evaluation.
These thresholds are general guidance. Your doctor interprets the results together with your symptoms, physical examination, and other test results.
02 / Understanding the procedure
When Is This Procedure Considered?
A doctor may consider this procedure in the situations below. The decision is always made after a thorough assessment.
- ABI Result Too High or UncertainWhen stiff ankle arteries make the ABI higher than 1.40 or impossible to measure.
- Diabetes or Chronic Kidney DiseaseArteries often harden in these conditions, so the TBI is more reliable than the ABI.
- Slow-Healing Foot WoundsHelps assess whether blood flow to the foot is enough for wound healing.
- Leg Pain When WalkingTo look for narrowed arteries as the cause of symptoms, especially if the ABI result is normal.
- Routine Diabetic Foot ChecksAs part of checking blood flow to the feet in people with diabetes.
- Monitoring After a ProcedureAssesses the results of artery widening or bypass surgery over time.
Situations to Consider First
- Amputated Big ToeThe measurement can be taken on the second toe, or another test is chosen.
- Open Wounds or Dead Tissue on the ToesThe cuff is not placed over a wound. The doctor chooses another toe or another test.
- Severe Pain When the Cuff Is InflatedThe test can be stopped at any time if you feel very uncomfortable.
- Dialysis Access or Past Breast Surgery on One ArmBlood pressure is measured on the other arm to avoid injury or swelling.
03 / Before the procedure
How Should You Prepare?
This test does not require any special preparation.
Food and medications. You may eat and drink as usual, and keep taking your regular medications.
Smoking, coffee, and exercise. Avoid smoking for two hours or more before the test, as well as coffee and strenuous exercise beforehand, because they can affect blood pressure and blood flow to the feet.
Keep your feet warm. Cold toes can make the result look lower. Wear socks and comfortable footwear, and tell the staff if your feet feel cold.
Clothing. Wear loose clothing so your upper arms and feet can be uncovered easily.
Previous results. Bring any ABI or duplex ultrasound results or records of blood vessel procedures. Tell the staff if you have foot wounds, dialysis access in your arm, or a history of breast surgery.
Unsure about the preparation instructions? Ask our team before the procedure.
04 / During the procedure
How Is the Procedure Done?
The test generally takes about 15 to 30 minutes and is often done together with an ABI test.
Resting
You lie on your back in a warm room for about 10 minutes so your blood pressure stabilizes. Your socks are removed, and your feet may be covered with a blanket or warmed if they feel cold.
Arm Blood Pressure
Blood pressure is measured in both arms with a regular cuff. The higher value is used for the calculation.
Big Toe Blood Pressure
A small cuff is placed at the base of the big toe, and a light sensor is placed on its tip. The cuff is briefly inflated until it feels tight, then slowly deflated until the sensor detects blood flow returning. The measurement is done on both feet.
Calculating the Result
The big toe pressure is divided by the higher arm pressure to get the TBI value for each foot. The results can usually be explained right after the test.
05 / Benefits and risks
Benefits and Risks Should Be Discussed Together.
Every medical procedure has benefits and risks. Your doctor will explain both for your situation before the procedure.
Benefits You Can Expect
- No Needles and No RadiationUses only a cuff and a light sensor, so it is safe to repeat at any time.
- Reliable in Stiff ArteriesRemains meaningful in diabetes and kidney disease, when ABI results are less reliable.
- Quick with Immediate ResultsCompleted in a short time, and the results can be explained right away.
- Assessing the Chance of Wound HealingBig toe pressure helps estimate whether blood flow is enough to heal a wound.
- Monitoring Over TimeUseful for tracking disease progression or the results of a procedure.
The benefits of a procedure are not a promise of a cure. Ask how the results will affect your care plan.
Risks You Should Know
- Discomfort from the CuffThe big toe may feel squeezed, tingly, or achy for a short time.
- Less Accurate Results When Feet Are ColdToe blood vessels narrow in the cold, so the feet are warmed beforehand.
- Hard to Measure in Certain ConditionsWounds, amputation, or very weak blood flow can make measurement difficult, so another test is needed.
- Pain in Feet with Very Poor Blood FlowThe cuff is inflated as briefly as possible, and the test can be stopped at any time.
Risks can differ from person to person. A full explanation and consent are given after an individual assessment.
06 / After the procedure
What Is Recovery Like?
There is no recovery period. You can go home right away and carry on with your usual activities.
Sensation in the big toe. Mild tingling or aching from the cuff will go away within a few minutes.
Results. Your doctor explains what your TBI value means and the next steps, for example medication, walking exercise, foot care, or further tests such as duplex ultrasound or CT angiography.
Foot care. If you have diabetes, check your feet every day and keep them clean, dry, and protected.
Warning signs to watch for. Go to the emergency room right away or contact the medical team if you experience:
- A foot or toes that suddenly turn cold, pale, or bluish
- Foot pain at rest that gets worse, especially at night
- A foot wound that gets worse, has pus, or turns black
Know the Signs That Need Prompt Care.
Follow the team's guidance on warning signs. If severe or sudden symptoms appear after the procedure, go to the nearest emergency department right away or call Heart Attack Center 1500 258.
07 / Team and support
Doctors and Procedure Support
The doctors below are listed for this procedure. Listed by name, not by ranking.
dr. Debby C. Soemitha, Sp.PD
Internal Medicine
Clinical focusDiabetes and Diabetes Complications · Obesity and Metabolic Disease
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dr. Emanoel Oepangat, Sp.JP(K)
Interventional Cardiology
Vascular Diagnostic and Therapeutic Center +1 center
Clinical focusCoronary Intervention · Peripheral Vascular Intervention
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dr. Suko Adiarto, Sp.JP(K), Ph.D.
Interventional Cardiology
Vascular Diagnostic and Therapeutic Center +1 center
Clinical focusCoronary Intervention · Peripheral Vascular Intervention
View ProfileAnkle-Brachial Index (ABI) Testing System
A needle-free test that compares blood pressure at the ankles and arms. The result is an index number that helps doctors detect…
The availability of technology and test support is confirmed with the team. Technology is chosen according to clinical need.
08 / Common questions
Before You Plan the Procedure.
Frequently asked questions about the TBI test. Your doctor will explain what the results mean for your condition.
What is the difference between a TBI test and an ABI test?
An ABI test compares the blood pressure at the ankle with the arm, while the TBI uses the pressure in the big toe. In diabetes, kidney disease, or older age, the ankle arteries can become stiff, so the ABI looks normal even though blood flow is reduced. Toe arteries rarely harden, so the TBI is used to complement the ABI. Both are often done together.
Does the TBI test hurt?
It is not painful. All you feel is pressure from the small cuff on your big toe for a few seconds while it is inflated, similar to having your arm blood pressure measured. Sometimes mild tingling appears and quickly goes away. If you have a wound or pain in your foot, tell the staff so the cuff can be placed carefully or on another toe.
What does my TBI value mean?
In general, a TBI above 0.70 is considered normal, while 0.70 or lower indicates narrowing of the leg arteries. A big toe pressure below 30 mmHg signals very poor blood flow, so wounds are slow to heal. These thresholds are only general guidance. Your doctor interprets the results together with your symptoms and other tests, so discuss your results with your doctor.
Why do my feet need to be warm during the test?
The small blood vessels in the toes narrow in the cold. As a result, the big toe pressure can read lower than it really is, and the result looks worse. That is why the test is done in a warm room, you are asked to rest beforehand, and your feet may be covered or warmed before the measurement begins.
Do people with diabetes need a TBI test regularly?
Diabetic foot guidelines recommend checking blood flow to the feet regularly, at least once a year, by feeling the foot pulses and with tests such as the ABI or TBI. More frequent checks may be needed if there is a wound, leg pain, or a previous abnormal result. Your doctor will set a suitable schedule for you.
What if my TBI result is low?
A low result indicates reduced blood flow to the foot. The doctor usually follows up with tests to locate the narrowing, such as duplex ultrasound or CT angiography. Treatment can range from medication, quitting smoking, walking exercise, and foot care to a procedure to restore blood flow if needed.
Sources and Medical Review
Translated from the Indonesian edition medically reviewed by dr. Suko Adiarto, Sp.JP(K), Ph.D..
Sources as cited in the Indonesian edition.
- Aboyans V, Criqui MH, Abraham P, et al. Measurement and Interpretation of the Ankle-Brachial Index: A Scientific Statement From the American Heart Association. Circulation. 2012;126(24):2890-2909.
- Høyer C, Sandermann J, Petersen LJ. The toe-brachial index in the diagnosis of peripheral arterial disease. J Vasc Surg. 2013;58(1):231-238.
- Fitridge R, Chuter V, Mills J, et al. The intersocietal IWGDF, ESVS, SVS guidelines on peripheral artery disease in people with diabetes and a foot ulcer. Diabetes Metab Res Rev. 2024;40(3):e3686.
- Gornik HL, Aronow HD, Goodney PP, et al. 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease. Circulation. 2024;149(24):e1313-e1410.
- Mazzolai L, Teixido-Tura G, Lanzi S, et al. 2024 ESC Guidelines for the management of peripheral arterial and aortic diseases. Eur Heart J. 2024;45(36):3538-3700.